ZX81 Listing for zx81rain.p


ZX81 program listing for **ZX81 RAIN**SLR/2023*

**ZX81 RAIN**SLR/2023* (zx81rain.p)

A further refinement of my z80 Digital Rain. For normal ZX81 users you’ll notice the drops start at random locations in the top half of the screen. For Chroma users, it adds different drop shades that are closer to the original.


SYSTEM VARIABLES

PROG  : 16509
D-FILE: 17028
VARS  : 17821
E-LINE: 17822
STKBOT: 17827
STKEND: 17827


LEGEND

9999 means line number
PRINT means treat as KEYWORD P


PROGRAM LISTING

   1 REM /**ZX81 RAIN**SLR/2023*
30413 LN DO PI5ORND5SLOW RNDö4LN
DEF PROC INKEY$F(IF LPRINT LET
CHR$ óY4CLEAR LN DPOKE PI/ STEP
                                
                                
                                
    ö4LN 7PIX5VAL RNDµ?£+LINE
LN 7PIFOR ¶?ööFOR LN 7PIFOR ñ4 ù
?ùQ TAN ?MTAB RND6?RNDE?RND""ö
HOME LN 7PIRETURN M AND )INKEY$ö
/LN 7PIDEF PROC UTAB RNDCHAR ?
LN SGN INKEY$SIN INKEY$CHAR U
DELETE PINEW 4?ASN £INKEY$LEN  ö
£LN LPRINT INKEY$E?RNDUTAB RND
CHAR LEN /LN SGN INKEY$JöôLN ùPI
?SINKEY$INKEY$ö?LN LPRINT INKEY$
E?RNDUTAB RNDCHAR OTAN FOR öPLN
7PILEN úFOR TAN RNDWHEN - ;25
CHAR õCOS ;(CLEAR TAN DEF PROC
FOR E?RNDLOAD INKEY$?UDELETE PI
NEW 4""ACS UNPLOT ?ACS WLN ñPI
Yô) TO COPY ;ACS UNPLOT ?TAN ?U
DELETE PINEW 4""GOSUB OFF£RND5
RUN ò;UTAB RNDREAD - ;ACS
UNPLOT ?TAN 5  GOSUB READ µ?
GOSUB READ ´NEW 3LINE 68PI)4 ; 
TAN OR LN ERROR ?Kò OR TAN LN
ONPIINT COPY COPY ñLOAD ?GOSUB ?
MDELETE PINEW 4""YSGOSUB ?TAN ñ
LOAD ?GOSUB ?NEW 4""JGOSUB ?Y
COPY MDELETE PITAN
   2 RAND USR VAL "16514"